Rotary tower crane



March 26, 1957 F. w. SCHWING 2,786,534

ROTARY TOWER CRANE Filed Sept. 7, 1954.

United States Patent ROTARY TOWER CRANE Friedrich W. Schwing, Wanne-Eickel, Germany Application September 7, 1954, Serial No. 454,585

Claims priority, application Germany September 7, 1953 3 Claims. (Cl. 212-144) This invention relates to rotary tower cranes.

The large dimensions of such rotary tower cranes render very difficult their transport as well as their mounting and demounting. It has, therefore, already been proposed to reduce the length of the parts of such. cranes to be transported by subdividing the tower and the crane beam. This known construction, however, has the disadvantage that the mounting and demounting of such cranes requires much time.

By the invention these disadvantages are avoided and a rotary tower crane is produced, which can be erected respectively mounted in a minimum of time and which can for the purpose of transport be brought to only low dimensions. These advantages are obtained according to the invention by such a construction of a tower crane, the tower and the crane beam consisting of parts of which are pivotally detachable and hingedly connected with another, that contrary to known constructions in which folding together of the parts is possible and takes part in only one plane, the connection of the parts with another is so that their folding together is possible in more than one plane.

Whereas the multiple folding together of tower and crane beam in one and the same plane results in a successive superposition of the parts and therewith in an undesirable big transportation height, folding in different planes according to the invention-i. e. further folding together of the parts initially only folded against another-preferably in crosswise direction to this first folding results in a shortening of the transportation length without increasing the transportation height.

From the drawings, which represent a preferred modification of the invention, Figures 1 and 2 show the erected crane in two different elevations.

Figs. 3 and 4 show the crane in two folded positions.

In the drawings 1 is the under-car which supports the upper-car 2 on which the lower tower part 3 with the joints 4 and the detachable connections 5 are fixed. The upper part 6 of the tower is connected with the lower part 3 by means of the joints 7 at 8.

The crane parts 9 and 10 are provided with the joints iii ' gether.

2,786,584 Patented Mar. 26, 1957 ice 11 and with the detachable connections 20. For the purpose of laying down the erected tower crane, the crane beam is lowered till it hangs down before the tower in the position shown in dotted lines in Figure 1. For the purpose of clearness in Figure l the joints 7 and 11 are shown as being arranged one asides the other, whereas, in fact, they cover another. To obtain this coaxial position, the crane beam may have in the plane of the joint the same width as the tower or alignment of the joint points 7 and 11 can be obtained by a projecting arrangement of the joint 11 or by swivelling the crane beam around the point designated with 13.

After loosening the connection 12 of the crane beam and 8 of the tower, the tower part 6 and the crane beam part 9 are together tilted sidewise around the axles 7', 7 and 11' 11 till they hang down aside of the tower part 3 as can be seen from Figure 3. After loosening of the connection 5, the tower together with the crane beam are tilted forwardly, so that the parts are then in their position for transportation as shown in Figure 4.

Erecting respectively mounting of the crane is performed in the inverse subsequence of the described tilting movements. For performing the tilting movements preferably the lifting jacks of the crane are used. Instead of this, however, also winches provided especially for this purpose can be used respectively can assist the lifting jacks of the crane. The ropes can remain on their place during the tilting processes or may be demounted.

What I claim is:

l. A tower crane comprising a substantially vertical tower mounted on a platform, a boom connected to said tower by a pivot about which said boom may be swung in a vertical plane from normal operating position at an angle to said tower to a position substantially parallel and closely adjacent to said tower, said tower and said boom each comprising at least two portions joined together by means including pivots, said portions being of such length that when said tower and boom are in parallelism said pivots included in said joining means are coaxial, whereby said tower and boom may be folded to- 2. The crane of claim 1 in which the mounting of said tower or said platform includes a horizontal pivot whereby said tower and boom may be lowered to horizontal position.

3. The crane of claim 1 in which the boom and the tower are of the same width at the location of said joining means.

References Cited in the file of this patent UNITED STATES PATENTS 1,232,168 Aronson July 3, 1917 2,521,861 Mathias Sept. 12, 1950 2,595,897 Shoemaker May 6, 1952 

